The ArcGIS API for JavaScript offers an alternative approach to working with client-side graphic features: the FeatureLayer.
FeatureLayer inherits from the GraphicsLayer but also offers additional capabilities such as the ability to perform queries and selections and filtering of data using definition expressions. The FeatureLayer can also be used for web-based editing, as we will see in a later chapter.
The main way in which the FeatureLayer differs from tiled and dynamic map service layers is that it doesn't perform the rendering server side. Instead, it sends the geometries and their associated attributes to the browser. The browser renders the features from the geometries and stores all their attribute data in memory.
Compare this to the tiled and dynamic map service layers that we have already seen, which are rendered on the server as images...